Schematics: Add indent-with-space option for schematic Lua table serialization

doc/lua_api.txt

@@ -2178,8 +2178,10 @@ These functions return the leftover itemstack.
     * "mts" - a string containing the binary MTS data used in the MTS file format
     * "lua" - a string containing Lua code representing the schematic in table format
     * `options` is a table containing the following optional parameters:
-    * If `use_comments` is true and `format` is "lua", the Lua code generated will have (X, Z)
+    * If `lua_use_comments` is true and `format` is "lua", the Lua code generated will have (X, Z)
     * position comments for every X row generated in the schematic data for easier reading.
+    * If `lua_num_indent_spaces` is a nonzero number and `format` is "lua", the Lua code generated
+    * will use that number of spaces as indentation instead of a tab character.
 
 ### Misc.
 * `minetest.get_connected_players()`: returns list of `ObjectRefs`

src/mg_schematic.cpp

@@ -309,14 +309,18 @@ bool Schematic::serializeToMts(std::ostream *os,
 
 
 bool Schematic::serializeToLua(std::ostream *os,
-	const std::vector<std::string> &names, bool use_comments)
+	const std::vector<std::string> &names, bool use_comments, u32 indent_spaces)
 {
 	std::ostream &ss = *os;
 
+	std::string indent("\t");
+	if (indent_spaces > 0)
+		indent.assign(indent_spaces, ' ');
+
 	//// Write header
 	{
 		ss << "schematic = {" << std::endl;
-		ss << "\tsize = "
+		ss << indent << "size = "
 			<< "{x=" << size.X
 			<< ", y=" << size.Y
 			<< ", z=" << size.Z
@@ -325,33 +329,34 @@ bool Schematic::serializeToLua(std::ostream *os,
 
 	//// Write y-slice probabilities
 	{
-		ss << "\tyslice_prob = {" << std::endl;
+		ss << indent << "yslice_prob = {" << std::endl;
 
 		for (u16 y = 0; y != size.Y; y++) {
-			ss << "\t\t{"
+			ss << indent << indent << "{"
 				<< "ypos=" << y
 				<< ", prob=" << (u16)slice_probs[y]
 				<< "}," << std::endl;
 		}
 
-		ss << "\t}," << std::endl;
+		ss << indent << "}," << std::endl;
 	}
 
 	//// Write node data
 	{
-		ss << "\tdata = {" << std::endl;
+		ss << indent << "data = {" << std::endl;
 
 		u32 i = 0;
 		for (u16 z = 0; z != size.Z; z++)
 		for (u16 y = 0; y != size.Y; y++) {
 			if (use_comments) {
 				ss << std::endl
-					<< "\t\t-- z=" << z
+					<< indent << indent
+					<< "-- z=" << z
 					<< ", y=" << y << std::endl;
 			}
 
 			for (u16 x = 0; x != size.X; x++, i++) {
-				ss << "\t\t{"
+				ss << indent << indent << "{"
 					<< "name=\"" << names[schemdata[i].getContent()]
 					<< "\", param1=" << (u16)schemdata[i].param1
 					<< ", param2=" << (u16)schemdata[i].param2
@@ -359,7 +364,7 @@ bool Schematic::serializeToLua(std::ostream *os,
 			}
 		}
 
-		ss << "\t}," << std::endl;
+		ss << indent << "}," << std::endl;
 	}
 
 	ss << "}" << std::endl;

src/mg_schematic.h

@@ -110,7 +110,7 @@ public:
 	bool deserializeFromMts(std::istream *is, std::vector<std::string> *names);
 	bool serializeToMts(std::ostream *os, const std::vector<std::string> &names);
 	bool serializeToLua(std::ostream *os, const std::vector<std::string> &names,
-		bool use_comments);
+		bool use_comments, u32 indent_spaces);
 
 	void placeStructure(Map *map, v3s16 p, u32 flags,
 		Rotation rot, bool force_placement);

src/script/lua_api/l_mapgen.cpp

@@ -1134,7 +1134,8 @@ int ModApiMapgen::l_serialize_schematic(lua_State *L)
 	SchematicManager *schemmgr = getServer(L)->getEmergeManager()->schemmgr;
 
 	//// Read options
-	bool use_comments = getboolfield_default(L, 3, "use_lua_comments", false);
+	bool use_comments = getboolfield_default(L, 3, "lua_use_comments", false);
+	u32 indent_spaces = getintfield_default(L, 3, "lua_num_indent_spaces", 0);
 
 	//// Get schematic
 	bool was_loaded = false;
@@ -1161,7 +1162,8 @@ int ModApiMapgen::l_serialize_schematic(lua_State *L)
 		schem->serializeToMts(&os, schem->m_nodenames);
 		break;
 	case SCHEM_FMT_LUA:
-		schem->serializeToLua(&os, schem->m_nodenames, use_comments);
+		schem->serializeToLua(&os, schem->m_nodenames,
+			use_comments, indent_spaces);
 		break;
 	default:
 		return 0;